MathType 6.0

MathType for Macintosh is a powerful interactive equation editor that lets you create mathematical notation for word processing, web pages, desktop publishing, presentations, and for TeX, LaTeX, and MathML documents.

MathType offers a large number of symbols and templates. Beside the exclusive Euclid math fonts, you can also make use of the 1000s of math symbols in fonts already on your computer, as well as math fonts you can download from the Internet.
MathType's Insert Symbol dialog allows you to explore the available symbols and insert them with a click or keystroke.

MathType works with many applications. In addition to Apple iWork '09, Microsoft Word and PowerPoint, use MathType to add equations to QuarkXPress and Adobe InDesign layouts, Excel spreadsheets, HTML pages, and many more applications and document types.
It also works with Wikipedia. Once you do your research on Wikipedia, you can copy the relevant equations for use in your own work. You can also use MathType to author new equations for Wikipedia.
MathType can add equations to virtually any application that has an Insert Object command or into which you can paste or drag a graphic.

The application offers you to create equations in two ways: by point-and-click editing with automatic formatting, and by TeX or LaTeX typing.

Also the application allows you to save expressions in the toolbar, color an expression, supports keyboard shortcuts, and is easy to use.